Exhaust system with post-operation cooling for a vehicle, and a method thereof

ABSTRACT

An exhaust system with post-operation cooling for a vehicle is provided. The vehicle generally has a heat generating device that generates exhaust gas. The exhaust system includes an exhaust gas conduit through which at least a portion of the exhaust gas is flowable and dischargeable, and at least one exhaust gas component in fluid communication with the exhaust gas conduit. The exhaust system also includes an air intake conduit through which outside air is flowable, and an air pump in fluid communication with the air intake conduit. The air intake conduit is in fluid communication with the exhaust gas conduit upstream of the at least one exhaust gas component. The air pump is configured to draw the outside air into the air intake conduit such that the outside air is supplied to the exhaust gas conduit to cool the at least one exhaust gas component.

TECHNICAL FIELD

The present invention relates to an exhaust system with post-operation cooling for a vehicle, and a method thereof.

BACKGROUND

Vehicle exhaust systems often include various components that utilize and/or treat the exhaust gas generated by a heat generating device, such as an internal combustion engine before the exhaust gas is discharged. Such components may include, but are not limited to, a turbocharger, a catalytic converter, a diesel oxidation canister, and the like. The exhaust gas heats the components to high temperatures when the exhaust system is in operation, i.e., the internal combustion engine is operating and generating exhaust gas. Once the vehicle has stopped and the internal combustion engine and engine fans are shut off, temperature excursions may occur within the components. The components may then radiate heat to other nearby thermally sensitive components in other systems within the vehicle. Currently, insulation shielding and external convection are used to mitigate the effects of the temperature excursions where the exhaust components are routed through thermally sensitive locations.

SUMMARY

An exhaust system for a vehicle is provided. The vehicle generally has a heat generating device that generates exhaust gas. The exhaust system includes an exhaust gas conduit in fluid communication with the heat generating device to receive the exhaust gas. At least a portion of the exhaust gas is flowable through and dischargeable from the exhaust gas conduit. The exhaust system also includes an exhaust gas component in fluid communication with the exhaust gas conduit. The at least a portion of the exhaust gas is also flowable through the exhaust gas component.

The exhaust system also includes an air intake conduit through which outside air is flowable. The air intake conduit is in fluid communication with the exhaust gas conduit upstream of the at least one exhaust gas component. The exhaust system further includes an air pump in fluid communication with the air intake conduit. The air pump is configured to draw the outside air into the air intake conduit such that the outside air is supplied to the exhaust gas conduit to cool the at least one exhaust gas component.

A vehicle is also provided. The vehicle includes a heat generating device configured to generate exhaust gas, and the exhaust system described above.

A method of cooling an exhaust gas component of the exhaust system described above is further provided. The method includes introducing outside air into the exhaust system and through the exhaust gas component to internally cool the exhaust gas component post-operation. This may be accomplished by drawing in the outside air by the air pump and supplying the outside air upstream of the exhaust gas component until at least one condition is satisfied. The condition may be when the air pump has been operating for a predetermined length of time, or when a temperature of the exhaust gas component reaches a predetermined temperature. The method finally includes turning off, by the controller, the air pump.

The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic flow diagram of an exhaust system for a vehicle; and

FIG. 2 is a schematic flow diagram illustrating a method of operating the exhaust system of FIG. 1 to cool an exhaust gas component of the exhaust system.

DETAILED DESCRIPTION

Those having ordinary skill in the art will recognize that terms such as “above,” “below,” “upward,” “downward,” et cetera, are used descriptively of the figures, and do not represent limitations on the scope of the invention, as defined by the appended claims. Any numerical designations, such as “first” or “second” are illustrative only and are not intended to limit the scope of the invention in any way.

Referring to the drawings, wherein like reference numbers correspond to like or similar components wherever possible throughout the several figures, an exhaust system 10 with post-operation cooling for a vehicle 12 is shown in FIG. 1. The vehicle 12 has a heat generating device 14 that generates exhaust gas 17. The heat generating device 14 may be, but is not limited to, an internal combustion engine.

The exhaust system 10 includes an exhaust gas conduit 16 or manifold in fluid communication with the heat generating device 14 such that it may receive the exhaust gas 17 from the heat generating device 14. At least a portion of the exhaust gas 17 is flowable through and dischargeable from the exhaust gas conduit 16.

The exhaust system 10 also may include various exhaust gas components 18, 20 in fluid communication with the exhaust gas conduit 16. The exhaust gas components 18, 20 may be located in the underhood or underbody portion of the vehicle 12 in close proximity to at least one external component 30 of another vehicle system (not shown). The exhaust gas 17 is flowable through the exhaust gas components 18, 20, each of which may interact with the exhaust gas 17 for a specific function depending upon the component. For example, as seen in FIG. 1, the exhaust gas components 18, 20 may be, but are not limited to, a turbocharger 18 and an exhaust gas treatment device 20. The exhaust gas treatment device 20 may be, but is not limited to, a diesel oxidation canister, a catalytic converter, and the like. While only one exhaust gas treatment device 20 is shown, it should be appreciated that there may be any number of exhaust gas treatment devices 20 in the exhaust system 10. Furthermore, while the exhaust gas treatment device 20 is shown downstream of the turbocharger 18, it should be appreciated that at least one exhaust gas treatment device 20 may be upstream of the turbocharger 18.

Generally, the exhaust gas 17 generated by the heat generating device 14 is at a high temperature and as such, heats the exhaust gas conduit 16 and the exhaust gas components 18, 20 as it flows through them. When the vehicle 12 and the heat generating device 14 are turned off, and therefore there is no exhaust gas flow and no engine cooling fans (not shown) are operating, temperature excursions may occur within the exhaust gas conduit 16 and the exhaust gas components 18, 20. Consequently, the exhaust gas conduit 16 and the exhaust gas components 18, 20 may rise to even higher temperatures, and may radiate heat to the external component(s) 30. As such, it is desirable to cool the exhaust gas conduit 16 and/or the exhaust gas components 18, 20 after the vehicle 12 and the heat generating device 14 are turned off to reduce the occurrence of such temperature excursions.

To accomplish this, the exhaust system 10 also includes an air intake conduit 22, through which outside air 23 is flowable, and an air pump 24 in fluid communication with the air intake conduit 22. The air intake conduit 22, in turn, is in fluid communication with the exhaust gas conduit 16 upstream of the exhaust gas component 18, 20 that is desired to be cooled. Generally, this may be the exhaust gas component 18, 20 that is furthest upstream in the exhaust gas conduit 16, i.e., closest to the heat generating device 14 (the turbocharger 18 in FIG. 1). This allows any exhaust gas components 18, 20 downstream (the exhaust gas treatment device 20 in FIG. 1) to be cooled as well. However, it should be appreciated that the air intake conduit 22 may be connected to the exhaust gas conduit 16 upstream of any exhaust gas component 18, 20.

The air pump 24 is configured to draw the outside air 23 into the air intake conduit 22 to be supplied to the exhaust gas conduit 16. The air pump 24 may be a low pressure, high volume pump, including, but not limited to, a vane pump. As explained above, the exhaust gas 17 heats the exhaust gas conduit 16 and the exhaust gas component(s) 18, 20 to a temperature above outside air temperature. As such, the outside air 23 introduced into the exhaust gas conduit 16 may cool the exhaust gas conduit 16 and the exhaust gas component(s) 18, 20, after which it may be discharged from the exhaust gas conduit 16, similar to the exhaust gas 17. As a result, the temperature of the external component(s) 30 may be reduced due to less available heat radiated from the exhaust gas component(s) 18, 20.

The exhaust system 10 may also include an air intake control valve 26 in fluid communication with the air intake conduit 22. The air intake control valve 26 may be located downstream of the air pump 24, and may be configured to control the flow of outside air 23 to the exhaust gas conduit 16 when the air pump 24 is in operation, as well as to prevent backflow of any exhaust gas 17 to the air pump 24 when it is not in operation. The air intake control valve 26 may be any open/close valve, including, but not limited to, a gate valve, and may be electronically actuated.

The exhaust system 10 may further include a temperature sensor 32 for each of the exhaust gas components 18, 20 and/or the external component(s) 30. The temperature sensor 32 may be configured to measure the temperature of the respective exhaust gas component 18, 20 and/or external component(s) 30 after and/or during operation to determine the operation of the air pump 24 and the air intake control valve 26, as explained in more detail below.

The vehicle 12 may include at least one controller 28 configured to control the operation of at least the air pump 24, i.e., turn the air pump 24 on and off, and the air intake control valve 26, i.e., open and close the air intake control valve 26. Specifically, the at least one controller 28 may be configured to determine how long the air pump 24 should operate based on at least one parameter and condition. The parameter may be the length of time that the air pump 24 operates. When the air pump 24 has been running for a predetermined length of time, the controller 28 may turn off the air pump 24, as well as close the air intake control valve 26. Alternatively or in addition, the parameter may be the temperature of at least one of the exhaust gas components 18, 20 and/or the external component(s) 30. When the temperature of at least one of the exhaust gas components 18, 20 falls to a predetermined temperature, the controller 28 may turn off the air pump 24 and close the air intake control valve 26. The predetermined length of time and/or the predetermined temperature may be programmed into the controller 28, and may be adjustable.

Referring now to FIG. 2, a method 100 for cooling at least one of the exhaust gas components 18, 20 in the exhaust system 10 is provided. Method 100 begins at steps 102 after the vehicle 12 and the heat generating device 14 have been turned off. At step 102, the controller 28 turns on the air pump 24 such that outside air 23 is drawn into the air intake conduit 22. After step 102, method 100 proceeds to step 104 at which the outside air 23 is deposited from the air intake conduit 22 to the exhaust gas conduit 16 upstream of the exhaust gas component 18, 20 desired to be cooled until at least one condition has been satisfied. As explained above, the condition may be that the air pump 24 has run for a predetermined length of time, or that the temperature of the exhaust gas component 18, 20 and/or the external component(s) 30 have fallen to a predetermined temperature. After step 104, method 100 proceeds to step 106 at which the controller 28 shuts down the air pump 24.

In embodiments in which the exhaust system 10 includes an air intake control valve 26, method 100 may include opening the air intake control valve 26 before depositing the outside air into the exhaust gas conduit 16. This may occur before, after, or simultaneously with the turning on of the air pump 24. Method 100 may also include closing the air intake control valve 26 after the condition has been satisfied. This may occur before, after, or simultaneously with the shutting down of the air pump 24.

The detailed description and the drawings or figures are supportive and descriptive of the invention, but the scope of the invention is defined solely by the claims. While some of the best modes and other embodiments for carrying out the claimed invention have been described in detail, various alternative designs and embodiments exist for practicing the invention defined in the appended claims. 

1. An exhaust system with post-operation cooling for a vehicle having a heat generating device that generates exhaust gas, the exhaust system comprising: an exhaust gas conduit in fluid communication with the heat generating device to receive the exhaust gas, at least a portion of which is flowable through and dischargeable from the exhaust gas conduit; at least one exhaust gas component in fluid communication with the exhaust gas conduit, the exhaust gas being flowable through the at least one exhaust gas component; an air intake conduit through which outside air is flowable, the air intake conduit being in fluid communication with the exhaust gas conduit upstream of the at least one exhaust gas component; and an air pump in fluid communication with the air intake conduit, the air pump being configured to draw the outside air into the air intake conduit such that the outside air is supplied to the exhaust gas conduit to cool the at least one exhaust gas component; and a controller in communication with the air pump such that the controller is capable of turning off the air pump, wherein the controller is programmed to turn off the air pump when a temperature of the at least one exhaust as component is less than a predetermined temperature.
 2. The exhaust system of claim 1 further comprising at least one air intake control valve in fluid communication with the air intake conduit, the at least one air intake control valve being configured to control the outside air supplied to the exhaust gas conduit and to prevent a backflow of the exhaust gas from the exhaust gas conduit to the air pump.
 3. The exhaust system of claim 1 further comprising a temperature sensor configured to measure the temperature of the at least one exhaust gas component.
 4. The exhaust system of claim 1 wherein the at least one exhaust gas component is a turbocharger.
 5. The exhaust system of claim 1 wherein the at least one exhaust gas component is an exhaust gas treatment device.
 6. The exhaust system of claim 5 wherein the exhaust gas treatment device is at least one of a diesel oxidation canister and a catalytic converter.
 7. The exhaust system of claim 1 wherein the controller is programmed to turn off the air pump after the air pump has been running for a predetermined amount of time.
 8. A vehicle comprising: a heat generating device configured to generate exhaust gas; and an exhaust system with post-operation cooling, the exhaust system being in fluid communication with the heat generating device and having: an exhaust gas conduit configured to receive the exhaust gas from the heat generating device and to discharge at least a portion of the exhaust gas; at least one exhaust gas component in fluid communication with the exhaust gas conduit, the exhaust gas being flowable through the at least one exhaust gas component; an air intake conduit through which outside air is flowable, the air intake conduit being in fluid communication with the exhaust gas conduit upstream of the at least one exhaust gas component; and an air pump in fluid communication with the air intake conduit, the air pump being configured to draw the outside air into the air intake conduit such that the outside air may be supplied to the exhaust gas conduit to cool the at least one exhaust gas component; and a controller in communication with the air pump such that the controller is capable of turning off the air pump, wherein the controller is programmed to turn off the air pump when a temperature of the at least one exhaust gas component is less than a predetermined temperature.
 9. The vehicle of claim 8 wherein the exhaust system further comprises at least one air intake control valve in fluid communication with the air intake conduit, the at least one air intake control valve being configured to control the outside air supplied to the exhaust gas conduit and to prevent a backflow of the exhaust gas from the exhaust gas conduit to the air pump.
 10. The vehicle of claim 8 wherein the exhaust system further comprises a temperature sensor configured to measure a temperature of the at least one exhaust gas component.
 11. The vehicle of claim 8 wherein the at least one exhaust gas component of the exhaust gas system is a turbocharger.
 12. The vehicle of claim 8 wherein the at least one exhaust gas component of the exhaust system is an exhaust gas treatment device.
 13. The vehicle of claim 12 wherein the exhaust gas treatment device is at least one of a diesel oxidation canister and a catalytic converter.
 14. The vehicle of claim 8 wherein the controller is programmed to turn off the air pump after the air pump has been running for a predetermined amount of time.
 15. The vehicle of claim 8 wherein the heat generating device is an internal combustion engine.
 16. The vehicle of claim 14 further comprising an air intake control valve in fluid communication with the air intake conduit, wherein the air intake control valve is configured to control the outside air supplied to the exhaust gas conduit and to prevent a backflow of the exhaust gas from the exhaust gas conduit to the air pump, the air intake control valve is movable between an open position and a closed position, and the controller is programmed to move the air intake control valve to the closed position after the air pump has been running for the predetermined amount of time.
 17. A method of cooling an exhaust gas component in an exhaust system of a vehicle, the method comprising; introducing outside air into the exhaust system and through the exhaust gas component using an air pump to internally cool the exhaust gas component post-operation of the vehicle; and determining a temperature of the exhaust gas component; and turning off the air pump at least when the temperature of the exhaust gas component is less than a predetermined temperature.
 18. The method of claim 17 wherein introducing of outside air into the exhaust system includes supplying the outside air upstream of the exhaust gas component.
 19. The method of claim 18 further comprising turning off the air pump after the air pump has been operating for a predetermined length of time.
 20. The method of claim 18 the exhaust system comprises an air intake conduit, an exhaust gas conduit in fluid communication with the air intake conduit and the exhaust gas component, an air intake control valve in fluid communication with the air intake conduit, the air intake control valve being configured to control the outside air supplied to the exhaust gas conduit and to prevent a backflow of the exhaust gas from the exhaust gas conduit to the air pump, and the method further comprises closing the air intake control valve after the air pump has been operating for the predetermined length of time. 